Float shoe



April 5, 1 960 T. E. ALEXAND-ER FLOAT SHOE I Filed Dec. 17, 1956 7 Ma 0/Z 4/ IN VEN TOR.

ATTOR/YEVJ United States Patent FLOAT SHOE Thomas E. Alexander, Houston,Tex.

Application December 17, 1956, Serial No. 628,841

' 8 Claims. (Cl. 166-225) This invention relates to new and usefulimprovements in devices for automatically filling well conduits.

One object of the invention is to provide an improved device forautomatically controlling the filling of a string of well casing, or thelike, as it is being lowered in the well bore, the fluid levelinternally of the casing being prevented from rising above apredetermined level which is below the fluid level in the well boreexternally of the well.

Various types of devices for controlling the filling of well casing havecome into general use and employ valves which are operated by thepressure differential thereacross. One such type of device isillustrated in the patent to Baker, No. 2,717,647, wherein a tubularvalve member presenting different areas at its upper and lower ends isactuated by the diiferential in pressure acting upon said ends. However,in order to assure actuation by the pressure difierential it isnecessary that the exterior of the valve member and the inner surface ofthe housing in which the member is slidable be shouldered or steppedwith suitable sealing means being provided between said member andhousing. This arrangement results in an annular space between a portionof the valve member and its housing which is necessarily atsubstantially atmospheric pressure. When the device is lowered into theWell, the interior of the tubular valve, as well as its ends, aresubjected to the well pressures and to the relatively high hydrostatichead pressures of the fluid within the well. However the annular spacesurrounding a portion of the valve is at substantially atmosphericpressure and this condition produces an excessive difierential acrossthe sealing means on the exterior of the valve member which may causeleakage; further, the lesser pressure surrounding a portion of themember with the higher pressure acting internally thereof, may result inan outward or radial distortion or expansion of the member to such anextent that free movement of the member within its housing is interferedwith.

It is, therefore, an important object of this invention to provide adevice, of the character described, which employs a tubular orsleeve-like valve member but which is so constructed that detrimentaland undesirable pressure difierentiais interiorly and exteriorly thereofare eliminated and also excessive pressure differentials across thesealing elements of the valve member are not present.

Another object is to provide a device for controllably filling a wellcasing, wherein a tubular valve member, having its wall of asubstantially constant, efiective crosssectional area, is movable withina housing and is arranged to co-act with a valve seat to control flowinto the well casing; the device also including a novelforcetransmitting assembly which is associated with one end of. thevalve member and which functions in co-opera-v tion with the member tocontrol the position thereof in accordance with the differential inpressures interiorly,

and exteriorly of the casing to control filling in a desired manner.

A further object is to provide a device of the character described,wherein the upper end of the tubular valve member is slidable within anannulus, with said annulus having an enlarged upper end within which aforce-transmitting element of larger cross-sectional area than the valvemember is reciprocable; that portion of the annulus between the upperend of the valve memher and the lower end of the force-transmittingelement containing a non-compressible liquid which functions to transmitmovement of the member and element to,

each other, whereby different efiective areas may be presented to thepressures interiorly and exteriorly of the well casing without requiringa valve member of varying cross-sectional area which results in therequirement of an air space in surrounding relationship to a portion ofthe valve member.

A particular object is to provide a device, of the' character described,which includes a hinged type valve seat element, together with animproved means for normally maintaining the seat element in position toco-act with the valve member; said seat element being releasable fromits normal position by the application of a predetermined pressure sothat said seat element may thereafter function as an upwardly closingback-check The construction designed to carry out the invention: will behereinafter described, together with other fea-" tures thereof.

The invention will be more readily understood from a reading of thefollowing specification and by reference to the accompanying drawingsforming a part thereof,

wherein an example of the invention is shown, and wherein:

Figure 1 is a longitudinal sectional view of a device, constructed inaccordance with the invention and illus trating the valve member inclosed position preventing upward flow of fluid into the casing,

Figure 2 is a transverse, sectional view, taken on the line 2-2 ofFigure 1,

Figure 3 is a transverse, sectional view, taken on the line 3-3 ofFigure 1,

Figure 4 is a partial longitudinal sectional view, il-

lustrating the movement of the valve member with' respect to the valveseat element, the latter being in a position connected with the housing,and

Figure 5 is a view, similar to Figure 4, with the valve seat element inreleased position.

The device constituting the present invention is what is commonlyreferred to as a casing or cementing shoe, or collar and is arranged tobe connected near or to the;

lower end of a string of well casing or pipe 16 which is adapted to belowered through the fluid within a well bore. It is pointed out,however, that the devicemay be con. nected at any desired intermediatepoint in the casing 01';

pipe so that in such event it may be considered as a casing collarforming part of the string.

-As illustrated in Figure 1, the device includes an outer-i V tubularbody 11 which has a threaded box 12 at its upper" end for connectionwith the lower end of the casing or;

Fatented Apr. 5, 1950.

, assembly and may be provided with an axial bore 14a.

Thefvalve assembly is of the type which will control the entry of fluidfrom the well bore into the casing Orwell pipe 1d during the loweringmovement, but when the string has been lowered to the desired elevationin the well bore, the valve assembly can be placed in ac'o'ndition inwhich upward flow of iiuid into the well casing will be shut 05;however, fluid m'ay'be pumped down weirdly through the casing or pipe toperform a or other operation] The valve assembly A includes an outershell or casing which ha's'a bore 36 extending entirely therethrougli.The upper portion 17 of the'bore o'f'the shell is enlarged in diameter,whereby an in tcrnalannular shoulder'18 is formed therein. Asillustrated, the lowerend of the shell 15 terminates in alignment withthe lower end of the cementitious material 14 which is at a point spacedabove the extreme lower end of the outer body 11.

Co-acting with the shell 15 to form an annular space or chamber 19 whichwill hereinafter be referred tofas an annulus 19 is an inner sleevemember 20 and as; illustrated this sleeve is provided with an annularflange 21' at its upper end which overlies and rests upon th'e upper endof the she l 15; however for convenience of an upward passage throughthe device is provided. The

lower end of the sleeve 20 terminates at some distance above the lowerend of the shell 15 as is clearly'shown in Figure l. A plurality ofopenings or ports 23.extend' radially through the sleeve 20 justbelowthe flange 21 and these openings establish a communication betweenthe bore 22 of the sleeve and the upper end of the annulus 19 which isformed between the sleeve 2%) and the shell 15;

By reason of the annular shoulder or oil-set 18, it will be evident thatthe annulus 19 is of greatercross-sectional area above said shoulder sothat the lower portion of the annulus -is in fact somewhat reduced incross-sectional area. An annular value member 24.has its upper portionslidable within the lower portion of the annulus 19 and said valvemember is movable axially within the annulus.

A sealing ring 25 seals between the bore of the'valve member and theexterior of the sleeve 20, while sealing rings 26 seal between theexterior of the valve member and the bore'of the shell. An inwardlydirected flange 27 V isformed on the lower end of the valve member andis provided with a bevelled seating surface 28 on its under side. .Theflange functions to limit the upward movement of the valve member 24 byengagement with the lower end of the sleeve 20; downward movement of thevalve member is limited by a stop. screwn29"which is, f suitably securedwithin the lower portion of the wallpiston or collar 30 is disposedwithin the larger upper portion of annulus 19, it has an effectivecross-sectional .area which is greater than the effectivecross-sectional area of the valve member 24. Confined between the piston30 and the upper end of the valve member is a suitable liquid 33whichrnay be oil or some other noncompressible fluid. Since the openingsor ports 23, which extend through the upper end of the sleeve 29,communicate with the upper end 'of the annulus 19, it is apparent thatthe upper surface of the piston or collar 30 is exposed to the pressurewithin the bore of the sleeve 20,

which, as has been stated, is in communication with the bore of the wellcasing or pipe 1i} in which the device is connected. To assure that thepressure interiorly of the well casing will act upon the piston orcollar 30 at all times, the upper surface of the piston or collar isprovided with an annular projection 34 which, when the piston is in itsfully raised position, wilhngage the under side of the flange 21 of thesleeve 259, and will prevent the upper surface of said piston fromsealing with the under sideof the flange. Any pressure acting upon theuppersurface of the piston'fiii will be transmitted through the liquid33 to the upper end of the valve member 24; similarly, any pressureacting against the under sideof the valve member 24, which would tend tourge the valve upwardly, will be transmitted through the liquid 33 totheunder side of the piston 30 and will tend to slide the same in anupward direction. Secured to the lower end of the valve member 24 is avalve seat'elernent 35. This element is generally circular in shape'andis provided with an extension or mounting lug 35 which is located at oneradial point and this lug isadapted to be pivoted on a pin 37 betweensupporting cars 58 (Figure 3), whereby the valve seat element is hingedto the lower end of the valve member, the supporting cars 38 beingsuitably secured or formed integral with said valve member. The element35' is formed with an annular surface 39,, which is engageaole withtheseat in'g s'uri'ace 28, at the lower end of the valve. Since the element35- is pivoted at 37 to. the valve member 24, it will apparent thatupward movement of the valve memher will result; in an upward movementof the lug 36, which will tend to, move the seat element upwardly withthe valve member. 7

In order to disengage the seating surface 25 of the valve mmeber 24 fromthe co-acting' surface 39, upon an upward movement of the valve member,the valve seat element 35 is formed with longitudinal grooves {it provided in opposite sides of a portion 46' of the valve (Figure 3))Engaged within each groove 41 is a restraining pin 42, each pin havingits outer end threaded through the outer shell15 of the valve assembly.With the pins 42 engaged within their respective grooves, as shown inFigure 3', an upward movement of the valve member, which will result inan upward movement of the hinge pin 37 will cause the valve seat element35 to be swung in the manner shown in Figure 4. Atthis time theretaining pins 42 will prevent upward travel of the valve seat element35 but will permit a swinging movement thereof because the pins will ineffect move along their respective grooves 41. Therefore, so longas thepins 42 are engaged with the grooves, an upward movement of the valvemember 24 will result in an unseating of the valve member from the seatelement and will allow a flow through the bore of the valve assembly.

The restraining pins 42 are capable of being fractured or broken, and ifdesired, may be provided with annular grooves 43 which will facilitatefracturefat "this point. By applyingv a downward pressure from withinthe well casing or pipe against the valve seat element, the valve memberhaving the valve seat element secured thereto is urged'downwardlyL' Theapplication of pressure against the valve memberand against'the seatelement to. a predetermined degree will result in fracturing or breakingthe connecting pins 42 and thereafter the valve seat ele cut 35 may beswung downwardly. in the manner. shown in Figure 5. Thereafter, the seatelement is merely hinged at 37 to the valve member and will function asa baclr check valve to prevena upward flow into the casing or pipestring. If desired, a spring (not shown) may surround the hinge pin inthe usual manner and may urge the seat element toward a closed position.However, any pressure below the valve member and seat element willfunction to move the seat element to a closed position. it is noted thatthe extension to on the lower surface of the seat element may have aninclined or bevelled end as indicated at 4-4, and when the valve swingsto an open position as shown in Figure 5, the bevelled surface isdisposed below the lower end of the shell 15. With this arrangement anyupward movement of the valve member 2 Within the annulus will cause thisbevelled surface 4-4 to engage the lower end of the shell and this w'dlresult in moving the element 35 into the path of the pressure. Thereforeit is assured that the valve seat element 35 will move to a closedposition.

The operation of the device is believed obvious from the foregoing. Theparts are in the position shown in Figure 1 and the device is connectedto the well casing or pipe which is to be lowered into the well. Thelower end of the valve member 24 is being acted upon by the pressure ofthe fluid which is present in the area outside of the well casing orpipe and this pressure is urging the valve member to a raised positionso that the upper portion of the valve member is being urged upwardlywithin the annulus 19. At the same time the pressure within the wellcasing or pipe is acting through the ports 23 against the upper surfaceof the piston or collar 39 and is urging the collar downwardly. Theforces applied to the upper surface of the piston, which is of a largercross-sectional area than the efiective cross-sectional area of thevalve member 24, are transmitted downwardly through the liquid 33 to thevalve member; at the same time the upward forces acting against thevalve member are also transmitted through the liquid to the piston orcollar. By controlling the areas of the piston or collar 39 and theefiective cross-sectional area of the valve member 24, a desiredoperation of the valve assembly may be accomplished.

Assuming that the pressure exteriorly of the casing or pipe, that is,the pressure acting on the under side of the valve member 24, issufiiciently greater than the pressure acting against the piston orcollar, the valve member is moved upwardly within the annulus l9 andsuch upward movement results in a swinging of the valve seat element3:": in the manner shown in Figure 4. This permits the entry of fluidinto the well casing or pipe and entry of the fluid continues until thepressure within the pipe builds up sufiiciently to urge the piston orcollar 30 in a downward direction against the pressure acting on thevalve member. When this occurs the parts are returned to the positionshown in Figure 1. This action of the valve continues as the pipe orcasing is lowered within the well bore and thus fluid is automaticallyadmitted to the interior of the casing or pipe during the lowerngoperation. The relationship of the area of the upper end of the pistonor collar St to the effective cross-sectional area of the tubular valvemember 24 will determine just how much fluid is admitted and what therelationship of the fluid column inside the well pipe or casing to theiiuid level outside the casing will be.

it might be pointed out that by providing the liquid edium 33 as theforce transmitting means between the an air space between the piston-30and valve member, instead of being substantially filled with liquid, apressure differential across the wall of the sleeve would be present andthere would be a tendency for the sleeve to be distorted radiallyoutwardly so as to cause a binding of the movement of both the pistonand the valve member within the annular cylinder. Furthermore, becauseof the same forces being present on each side of the piston at alltimes, the sealing rings 31 and 32 of the piston are never subjected toa pressure differential thereacross. With respect to the seals 25 and 26on the valve member, the maintenance of the pressure in the area betweenthe upper end of the valve member 24 and the lower surface of theannular collar Sti reduces or minimizes the pressure difierential whichwill be present across these seals under all operating conditions.

After the device has been lowered to the desired position, within thewell bore, a pressure may be built up within the well casing or drillpipe and this pressure will be directly applied to the valve seatelement 35. Through this element the pressure is transmitted to thefrangible pins 42 and upon these pins being fractured, the valve seatelement 35 is released for actuation as a back check to prevent upwardflow of fluid into the well casing or pipe. It is noted that when thepins 42 are engaged within their respective grooves 41, in the valveseat element 35, these pins function as the downward limit of movementof the annular valve member 24. However, after these pins have beenfractured, the downward movement of the valve member 24 is limited bythe stop 29 (Figure 5). After the valve seat element 35 has beenreleased, it may fall to the position shown in Figure 5 if the pressurewithin the pipe is greater than that below the assembly, and therefore afree downward fiow of fluid may occur. in the event of a build up of agreater pressure below the assembly, the valve seat-elementfis will beswung upwardly to engage the seating surface 23. As explained, thismovement of the valve seat element would be assisted by the bevelled orinclined surface 44 striking the lower end of the shell 15 as the valvemember 24 began to move upwardly. The co-action between this inclinedsurface and the lower end of the shell would swing the valve seatelement into the path of the pressure and would assure closing. However,if desired, a small spring could surround the pin 37 which would tend toconstantly urge the seat element toward a closed position.

The liquid 33 which is disposed between the piston or collar 30 ad theupper end of the tubular valve mernber 24 may completely fill thisspace. However, if de sired, a slight air space could be provided. Theprovision of a slight air space between the upper surface of the liquid33 and the under surface of the piston or collar 30 would result in aslower opening of the tubular valve member 24 because pressure actingagainst the under side of the valve would have to move upwardly asufiicient distance to first compress the slight amount of air beforeany upward movement would be accomplished to move the piston or collar3%) upwardly within the annulus. Of course, after the valve once opens,the operation would be identical.

The foregoing disclosure and description of the invention isillustrative and explanatory thereof and various changes in the size,shape and materials, as well as in the details of the illustratedconstruction, may be made within the scope of the appended claimswithout departing from the spirit of the invention.

What i claim is:

1. A device for controlling the filling of a well pipe including atubular body having a valve assembly therein comprising, a tubularmember having a bore therethrough, an annulus within said tubular membersurrounding said bore and having an open lower end and a closed upperend, a tubular valve member having its upper portion reciprocable withinthe lower portion of enemas a annulus, eans limiting the movement ofsaid valve the valve seat element to control flow through the tubularmember, an annular piston reciprocable within the upper portion of theannulus, a liquid within the annulus between the piston and the'upperend of the valve-mem ber, the lower end of thevalve member having aneffective pressure area exposed to the pressure of the fluid below thebody, and poit means establishing communication between the interior oft e tubular member and that area of the annulus above the piston wherebythe upper effective area of the piston is exposed to the pressure of the'fiuid within the well pipe, said upper effective area of the pistonbeing greater than the effective pressure area of the'lower end of thevalve'member.

2. A device as set forth'in claim 1 together with means for pivotallysecuring the valve seat element to the valve member, and means forreleasably securing said valve seat element to the tubular memberwhereby upwardmovement of the valve member causes a swinging of thevalve seat element to disengage the valve member from said seat. j

3. A device as set forth in claim 1, together with means for pivotallysecuring the valve seat element to the valve member and means forreleasably securing said valve seat element to the tubular memberwhereby upward movement of the valve member causes a swingingof thevalve seat element to disengage said member from said seat,

the releasable securing means for the valve seat element beingdisconnected by application of downward pressure thereto, whereby saidvalve may subsequently function as aback check preventing upward fiowthrough the tubular member. I v a 4. A'device of the characterdescribedcomprising, a tubular body, a tubular casing axially mounted inthe body, a cylindrical sleeve mounted axially within the casing andspaced from the internal wall thereof, the annular space between saidtubular member and sleeve forming an annulus open at its lower end, atubular valve member having its upper end slidable between predeterminedlimits within the lower portion of the annulus, a valve'seat within thecasing below the valve member and engageable by the lower end of thevalve member to close off flow through the sleeve, disengagement of saidvalve member from the valve seat allowing flow through the 'sleeve,anannular piston within the upper portion of the} annulus, a liquidbetween said piston and the upper end of the valve member, and portmeans for establishing communication between the interior of the sleeveand the upper end'of the annulus above the piston so that the uppersurface of the piston is exposed to the pressure of the fluid within thesleeve, the lower end of the valve member being exposed to the pressureof the fiuid below the body, said piston, liquid and valve member beingmovable with respect to the valve seat by the pressures acting upon thesurface of said piston and the lower surface of said valve member.

' 5. A device as set forth in claim 4 wherein the effective as theelfective pressure area of the lower end of the valve member.

6. A device for automatically filling well conduits including, a tubularbody adapted to be secured to'a con duit section to be disposed in awell bore and having a valve assembly therein comprising, a tubularmember having a bore therethrough, a valve seat in the lower portion ofsaid bore in the tubular member, said tubular member having an annulusformed therein, which annulus is spaced upwardly from said valve seat,the upper portion of said annulus being of a larger cross sectional areathan the lower portion thereof, an annulus valve member having its upperportion slidable within the lower end of the annulus and movablerelative to the valve seat to open or close off flow through the tubularmember, the lower end of the annular valve member being exposed to thepressure of fluid below the body, a forcetransmitting element slidablein the upper enlarged portion of the annulus, a liquid in said annulusbetween said element and the upper end of the annular valve member, andport means conducting the pressure of the fluid above the'tubular memberwithin the conduit against the upper surface of the force-transmittingelement.

7. A device for automatically filling well conduits including, a tubularbody adapted to be secured to a conduit section to be disposed in a welland having a valve assembly therein comprising, a tubular member, saidtubularmember having a bore therethrough, a valve seat mounted in thelower portion of the bore and extending part way thereacross, saidtubular member having an annulus formed therein which is spaced upwardlyfrom said upper end of the valve member and the lower end of the pistonfor transmitting movement from one to the other, the lower end of thevalve member being exposed to the pressure of the fluid below the body,and port means in theupper portion of the tubular member andestablishing communication between the bore above the valve seat and theannulus above the piston.

8. A device as set forth in claim 7 together with'a pressure seal meanscarried by the valve member for sealing between the walls of the annulusand the surfaces 7 of the valve member,'and additional seal means onsaid piston for sealing between the piston and the annulus.

Referenees't'iited in the file of this patent UNITED STATES PATENTS 7

